Dennis,
I use a simple hex dump for expediency. This misses files with a nonzero
user block, but I think those are pretty rare in the climate community.
For example, here is one of the test files in the latest Unidata distro.
But I get the same result with a locally created file.
mac56:~/netcdf/netcdf-c-4.4.1-rc2/nc_test4 55> od -tx1 -N9
ref_hdf5_compat2.nc
0000000 89 48 44 46 0d 0a 1a 0a 00
0000011
The superblock version number is the 9th (last) byte.
This number matches what is reported by ncdump -hs in the new release. I
have no reason to doubt the result from H5Pget_version.
--Dave
On Fri, Jun 3, 2016 at 4:59 PM, dmh@xxxxxxxx <dmh@xxxxxxxx> wrote:
> HDF says the (superblock format) differences are:
> Version 0 is the default format
> Version 1 is the same as version 0 but with the “Indexed Storage
> Internal Node K” field for storing non-default B-tree ‘K’ value.
> Version 2 has some fields eliminated and compressed from superblock
> format versions 0 and 1. It has added checksum support and
> superblock extension to store additional superblock metadata.
> Version 3 is the same as version 2 except that the field “File
> Consistency Flags” is used for file locking. This format version
> will enable support for the latest version.
> It is possible that the H5Pget_version indicates not the true number,
> but rather the lowest externally detectable version number or some such.
> Do you have a pure hdf5 1.10 file to see that superblock number is
> reported by ncdump -hs?
> Or did you do a hex dump to see what is actually in the superblock?
> =Dennis Heimbigner
> Unidata
>
>
> On 6/3/2016 4:11 PM, Dave Allured - NOAA Affiliate wrote:
>
>> Netcdf group,
>>
>> My team is starting to test netcdf-4.4.1-rc2 with the latest HDF5
>> library, currently 1.10.0-patch1. I see that netcdf-4 files are now
>> being generated with superblock version 0 for the first time in the
>> history of netcdf-4. Presumably this is a result of the recent format
>> compatibility fix in 4.4.1.
>>
>> All the older netcdf-4 files that I sampled, back to the original
>> netcdf-4.0 (2008), were created as superblock version 2.
>>
>> Are there any indications whether superblock 0 will be robust and
>> interoperable, going into the future?
>>
>> --Dave
>
>
